Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbine generators have gained increased attention in this regard. A modern wind turbine generator typically includes a wind turbine and a generator. The wind turbine typically includes a tower, gearbox, nacelle, and one or more rotor blades. The generator is typically housed in the nacelle. The rotor blades capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid. Further, wind turbine generators are typically grouped together in a wind farm, and may be onshore or offshore.
Wind power generation is typically provided by a wind “farm” having a large number (often 100 or more) of wind turbine generators. Each individual wind turbine generator typically experiences a unique wind force. Various other factors may additionally effect the performance of individual wind turbine generators during wind farm operation. Accordingly, the output power for each individual wind turbine generator may by individualized, and may vary from wind turbine generator to wind turbine generator.
As is generally understood, active power and reactive power are provided by each wind turbine generator. A park-level controller provides reactive power commands to the wind turbine generators, based on transmission grid needs. Typically, such commands are identical for each wind turbine generator. Such approach, however, has disadvantages. For example, due to apparent power limitations, an individual wind turbine which is generating a substantial amount of active power may be forced to curtail such active power generation in order to meet a required reactive power level. On a wind farm level setting, many individual wind turbine generators can be curtailed due to identical reactive power commands, thus resulting in significant active power losses.
Accordingly, improved wind farms and methods for operating wind farms are desired. In particular, improved methods and control systems which reduce curtailment and active power losses due to reactive power commands would be advantageous.